The present invention relates to a device for dispensing tickets, each being constituted by a segment detached from a continuous strip of paper. More precisely, the device of the invention is associated with a machine for printing tickets that constitute a receipt or a written record of a transaction such as a payment by means of a credit card. Still more precisely, one particular application of the device lies in being associated with a thermal printer.
There are two main varieties of ticket-dispensing machines: those in which the ticket is presented to the recipient already detached or predetached from the strip from which it is derived, and those in which the ticket is presented while still attached to the strip and it is by pulling on the ticket that it becomes detached from the strip where it passes over the sharp knife edge of a cutting blade. Machines of the second variety present the advantage of having cutting apparatus that is static, i.e. without any moving part, and thus simpler to maintain and operating without any need for power to be fed to move a moving cutting blade. In contrast, their drawback lies in the absence of a sharp and clean cut. The parting line is usually serrated or at an angle, and the tape is torn rather than being cut by the blade. If the blade had a sharp knife edge instead of serrations, then a difficulty arises at the point where cutting starts since cutting must start cleanly and must occur whatever the traction force applied to the ticket by its recipient. The most recent state of the art in this field consists in providing a V-shaped blade with a central point where the paper begins to be cut when the recipient pulls the paper. However, such a blade is complex and expensive to manufacture.
The invention proposes obtaining a cut that even if no better than that of a pointed blade is at least equivalent thereto, and to do with a blade that is much less expensive since it is straight-edged. The blade can have a cutting knife edge that is linear or serrated.
To this end, the invention relates to a device for dispensing tickets from a continuous strip of paper, each ticket being constituted by an end segment of the strip suitable for being grasped by a recipient of the ticket and detached by applying traction to said end, the device comprising a mechanism for pinching the paper along a line extending transversely across the strip, and downstream from this mechanism, a cutting blade extending substantially transversely across the strip, with the strip bearing against the cutting edge of the blade when the above-mentioned traction is applied. According to the invention, the cutting edge of the blade is formed by a straight-line segment that intersects the plane of the strip of paper in contact with the blade prior to cutting and containing the pinch line, with the projection of the blade onto said plane converging towards the pinch line from the point where the paper first comes into contact with the blade.
In other words, if the strip of paper is horizontal between the pinch line and the cutting blade, then the cutting edge of the blade slopes downwards and towards the pinch line. These two slopes make it possible firstly to create a cutting point at a location where traction force is concentrated when the segment of strip to be detached is pulled, thereby ensuring that cutting is started cleanly (at the high point of the blade), while its slope towards the pinch line is provided to correct for the angled line of cut that would normally arise from a blade having its cutting edge sloping in a vertical plane parallel to the pinch line.
When the device of the invention is associated with a thermal printer, the pinch line is the line of contact between the print head and the paper-driving capstan beneath it. It is not unusual for the force exerted by the print head on the capstan to be insufficient to ensure that the paper is properly pinched, and as a result it can happen that paper is allowed to slide while it is being cut. The paper is also retained by friction between the portion thereof which is wrapped around the capstan since the capstan is made of a material to which paper xe2x80x9cadheresxe2x80x9d if only to ensure that the capstan can drive it. The traction force, at least before cutting starts, is thus exerted in disadvantageous manner on the capstan which is subjected to interfering forces which, in the long run, harm proper operation thereof.
To remedy that, according to a feature of the invention, the blade is secured to a support mounted to pivot about a fixed axis substantially parallel to a straight line extending transversely relative to the strip of paper and situated beneath the cutting edge, being set back therefrom, said support presenting, upstream from the cutting blade, a jaw-forming portion which advances towards the strip to come against a fixed abutment when the end of the strip is subjected to the above-mentioned traction. This jaw and this abutment form an additional pinch mechanism which either prevents the paper sliding while it is being cut, or at least relieves the capstan of part of the traction force that results from the recipient taking hold of the ticket.
Other characteristics and advantages of the invention appear from the following description of various embodiments.